1. Field of the Invention
The present invention relates to a relay server and a relay communication system that enable resource sharing via a network.
2. Description of the Related Art
A communication system referred to as a Virtual Private Network (VPN) is known in the conventional art. The VPN is used, for example, to provide communication over the Internet between terminals connected to a Local Area Network (LAN) of a plurality of branch offices (base points) established in separate regions. Through the use of the VPN, each client terminal can share various resources (such as folders, files, etc.) held by apparatuses connected to another LAN arranged in a remote location.
A method for transmitting an electronic mail (e-mail) with a proper text message described therein and a file attached thereto, or the like, is commonly used, for example, as a method for exchanging files with a destination located inside and/or outside the VPN. Alternatively, a method for uploading a file by using a File Transfer Protocol (FTP) service and a method for sending by mail a recording medium, such as a CD-Recordable, on which a file is recorded, or the like, are used if necessary.
However, in the method for transmitting the file through the use of the e-mail attachment, it is necessary to both manage the e-mail in a mailbox, and organize and store the attached file in a desired folder each time. Moreover, when a file size is large, a transmitting side is required to set a mail server and to compress or divide the file due to limitations of mailbox sizes. Accordingly, a receiving side is required to perform a decompression process or a connecting process, and such operations have been troublesome.
When using the FTP service, although the service is suitable for the transmission of large files, troublesome operations such as setting up an account for the FTP service have been necessary. Alternatively, when sending the large file recorded on the recording medium such as a CD-Recordable by postal mail, the cost for such a medium and the mailing costs cause an increase in overall costs.
When using the FTP service, mailing method, or other similar method, if a message is desired to be sent along with the file, the message has to be transmitted separately via an e-mail, causing additional troublesome work. Moreover, some messages desired to be sent along with the file can be simple, such as “Attached please find XXX”, and the operation for creating such messages each time the file is transmitted have been troublesome when the files are frequently exchanged. Moreover, a party receiving the message and file is required to manage the received file by using file management software such as Explorer and to manage the message by using e-mail software. Therefore, there is room for improvement in terms of simplification of information organization.